What has Abigail done to Parris?

In Act Four, Reverend Parris arrives at the jail because several prisoners are to be hanged that morning.  We can tell, immediately, that this is a changed man from the one we knew a few months ago (in Act Three).  Miller describes him as "gaunt, frightened, and sweating in his greatcoat."  Even Danforth can see that he is troubled, and so Parris confesses to him that Abigail, his niece, has vanished.  Three nights ago, she said she was sleeping at Mercy Lewis's house, but Mercy told her father that she was sleeping at Abigail's.  Further, last night, Parris says that he discovered that Abigail had broken into his strongbox and stolen his life's savings: thirty one pounds.  Thus, she's robbed him and is likely far away now, on a ship.  (Parris says that Betty had heard Abigail talking about ships the week before.)